Governments have created postal services for collecting, sorting and distributing the mail. The postal service typically charges mailers for delivering the mail. Mailers may pay the postal service for this service by purchasing a stamp, i.e., a printed adhesive label or tape, issued by the postal service at specified prices, that is affixed to all letters, parcels or other mail matter to show prepayment of postage. Another means of payment accepted by the postal service is mail that is metered by a postage meter. Postage meters are approved by the Postal Service and licensed to the meter user by the meter manufacturer. A postage meter is an electromechanical device that maintains, through “electronic registers” or “postal security devices,” an account of all postage printed, and the remaining balance of prepaid postage; and prints postage postmarks (indicia) or provides postage postmarks (indicia) information to a printer, that are then printed and accepted by the postal service as evidence of the prepayment of postage.
Currently, mailers are able to use their desktop computer, a postal security device, and a printer to apply postage directly onto envelopes or labels while applying an address. The postage is applied in the form of an Information Based Indicia (IBI). The IBI consists of a two-dimensional bar code containing hundreds of bytes of information about the mail piece and certain human-readable information. The indicia include a digital signature to preclude the forgery of indicia by unauthorized parties. The postal security device is a unique security device that provides a cryptographic digital signature to the indicia and performs the function of postage meter registers.
In postage meters and computer postage systems, the need for security is absolute, because postage meters and computer postage systems are printing value; and, unless security measures are taken, one would be able to print unauthorized postage, i.e., postage for which no payment is made, thereby defrauding the postal service.
Although postage meters and computer postage systems have performed satisfactorily in the past and continue to perform satisfactorily, with the advancement of technology, it is becoming easier to print fraudulent indicia.